We focus on identifying candidate genes in restricted regions of the genome identified by linkage studies of complex genetic diseases, i.e. those which are not expected to show perfect cosegregation with any single locus. With our collaborators in NHGRI, we have identified transcripts in the vicinity of HPC1, a gene for early onset prostate cancer, and have obtained full-length cDNAs for more than ten new genes. We have begun to apply these methods to loci for bipolar disorder and schizophrenia. We have assembled unfinished sequence from the Human Genome Project to almost fully cover an approximately 15 cM region spanning the 13q32 region of chromosome 13 implicated by linkage analysis in both bipolar disorder and schizophrenia. We have identified more than 25 known genes and a growing number of new genes within this region. A number of these genes are attractive candidates and we have begun to characterize polymorphisms within these candidate genes.